SE123711C1

SE123711C1 -

Info

Publication number: SE123711C1
Authority: SE
Publication date: 1948-01-01

Description

Uppfinnare: D. T. Hollingsworth. Inventor: D. T. Hollingsworth.

Prieritet begard bin den 9 November 194 (Storbritannien). Priority was given to 9 November 194 (United Kingdom).

Vid framstallningen av en andmuff eller andtatning for en elektrisk hagspanningskabel avlagsnas enligt gangse bruk manteln och skarmen frau en lamplig langd av kabeln under kvarlamnande av kabelisoleringen bar. Denna inneslutes sedan i en rorformig isolator, vanligen av porslin, och det mellanliggande rummet fylles med isolerande olj a eller massa eller annat flytande isoleringsmaterial. Den undre anden av isolatorn monteras pa ett metallbottenstycke, som hopskarvas med kabeIns mantel. Den ovre linden av isolatorn uppbar andkontakten. In the manufacture of a duct sleeve or breather for an electric cord voltage cable, the sheath and the shield are removed from a suitable length of the cable while leaving the cable insulation bare. This is then enclosed in a tubular insulator, usually of porcelain, and the intermediate space is filled with insulating oil or pulp or other liquid insulating material. The lower end of the insulator is mounted on a metal base, which is joined together with the cable sheath. The upper linden of the insulator carried the duck contact.

Uppfinningen hanfor sig till en andmuff av detta slag och har sirskilt avseende pa en anordning for avagabringande av den tangsgaende fordelningen av elektrisk spanning over ytan av kabelisoleringen fran den &Eden, dar ledaren uttrader, till den anden, som dr jordad eller har jordpotential. mom denna ram omfattar uppfinningen anordnandet av ett ytskikt pit insidan och pa utsidan av det isolerande roret over hela (-less langd, vilka skikt tillsammans hava tillracklig elektrisk ledningsforrnaga for att astadkomma, att den langsgaende spanningsfOrdelningen pit roret och foljaktligen pa ytan av kabelisoleringen bestdmmes av spanningsfallet till foljd av lackningsstrommen genom dem och icke namnyart stares genom kapacitiva verkningar. Vidare Or det yttre skiktet vasentligt mera ledande On det inre skiktet. Dessa forhallanden kunna uppnas utan att lackningsstrommen blir storre On den kan matas i mikroampere. Foljaktligen är fOrlusten till MIA av lackningsstrommen forsumbar. The invention relates to a duct socket of this kind and relates in particular to a device for delivering the tangential distribution of electrical voltage across the surface of the cable insulation from the & Eden, where the conductor exits, to the other, which is grounded or has earth potential. In this context, the invention encompasses the provision of a surface layer pit inside and outside the insulating pipe over the entire length, which layers together have sufficient electrical conductivity to ensure that the longitudinal voltage distribution in the pipe and consequently on the surface of the cable insulation is determined by the voltage drop due to the lacquer current through them and non-namyart stares by capacitive effects.Furthermore, the outer layer is significantly more conductive On the inner layer.These conditions can be achieved without the lacquer current becoming larger On it can be fed into microamperes. the lacquer stream is negligible.

Det torde framga air ovanstitende forklaring, att ett skikt, som har gar under benamningen ett ledande skikt, icke Or en god le-dare i uttryckets vanliga betydelse. Det dr ledande endast i jamforelse med det isolerande material, av vilket det uppbares. It should appear from the above explanation that a layer, which has under the name a conductive layer, is not a good conductor in the usual sense of the term. It is conductive only in comparison with the insulating material from which it is obtained.

Betingelserna for tillforsakrande av de onskade verkningarna av det ledande skiktet dro, att detta skikt skall vara i huvudsak sammanhangande over hela den yta, pa vilken det Or anbragt, och skall hava i huvudsak likformigt motstand per langdenhet i hela roret. Sammanhang i den med rorets axel parallella riktningen Or madvandigt. Periferiellt sammanhang Or icke av sit stor betydelse, ty ett antal remsor av ett material tried lamplig ledningsformaga anbragta i kingdriktningen och skilda at I omkretsriktningen, sit att de tacka hela ytan av roret med undantag av smala gap raeIlan remsorna, skulle vara effektivt. The conditions for securing the desired effects of the conductive layer meant that this layer should be substantially coherent over the entire surface on which it was applied, and should have substantially uniform resistance per unit length throughout the tube. Context in the direction parallel to the rudder axis Or edible. Peripheral context Is not of great importance, for a number of strips of a material with a suitable conductor shape arranged in the king direction and separated in the circumferential direction, sit that they thank the whole surface of the tube with the exception of narrow gaps in the strip, would be effective.

Att det yttre skiktets ledningsfOrmaga gores vasentligt storre On det inre skiktets har till foljd, att sp .nningsfordelningen i langdriktningen icke advarligt stores genom okning av den yttre ytans ledningsformaga till foljd av utfallning av fuktighet eller smutsbelaggning. Narvaron av skiktet pa insidan av roret erbjuder en spanningsreglerande yta 'Ara kabeldielektriket och avagabringar approximativ likhet mellan potentialen i varje punkt pa den inre ytan och det omedelbart intill liggande omradet pa den yttre ytan, sit att rorets isoleringsmaterial befrias fran radiell pakanning i stor utstraekning. As a result of the conductivity of the outer layer being substantially greater, the consequence of the inner layer is that the stress distribution in the longitudinal direction is not adversely increased by increasing the conductivity of the outer surface as a result of precipitation of moisture or dirt coating. The presence of the layer on the inside of the pipe offers a voltage regulating surface to the cable dielectric and provides approximately similarity between the potential at each point on the inner surface and the immediately adjacent area on the outer surface, so that the pipe insulation material is largely free of radial packing.

Vid derma form av andmuff kan det isolerande roret vara gjort och Or foretradesvis gjort med endast ett litet fritt mellanrum Over kabelisoleringen. In this form of duct sleeve, the insulating pipe may be made and preferably made with only a small free space over the cable insulation.

Det isolerande raret Or foretrddesvis bildat av porslin med de ledande skikten fratnbragta genorn ledande glasyrer. Larnpliga ledande glasyrer kunna framstallas och anbringas sasom angives i den hrittiska patentskriften nr 577 748. Andra former av for och ledande skikt kunna emellertid anvandas. Exempelvis kan riiret var gjort av bakelitimpregnerat pap-per eller annat icke-fibrost material, och de ledande skikten kunna vara av metallisk malarfdrg eller metallfolie. Dessa fOrslag givas endast som exempel och Oro icke uttommande. The insulating layer Or is preferably formed of porcelain with the conductive layers removed from the conductive glazes. Applicable conductive glazes can be prepared and applied as disclosed in U.S. Patent No. 577,748. However, other forms of liner and conductive layers may be used. For example, the fabric may be made of bakelite impregnated paper or other non-fibrous material, and the conductive layers may be of metallic paint or metal foil. These suggestions are given by way of example only and concerns are not exhaustive.

Da det isolerande roret dr av stor langd, itr det fordelaktigt att dela langden i flera — — sektioner och anordna utjamnande fiirbindningar mellan de inre och yttre skikten vid nagra av eller alla skarvarna mellan sektionerna. Since the insulating tube is of large length, it is advantageous to divide the length into several sections and to provide smoothing connections between the inner and outer layers at some or all of the joints between the sections.

Bifogade ritning visar ett praktiskt tillampningsexempel pa upplinningen, varvid rite. ningsfiguren ar en central langdsektion genom en andmuff. delta exempel ar det isolerande rOret av porslin med de ledande skikten pa de inre och tire ytorna astadkomna inedelst glasyrer. De streckade hnjerna under rOrets ytor aro avsedda alt antyda fOrefintligheten av de le-dande skikten pa ytorna. IlOret Sr gjort 1 Ire sektioner 15, 10 och 17. Nar de anvandas liiisaninans passa de for en sarskilt hog spanning. FLU- en hire spanning kan Iva sektioner eller en enda sektion anyandas alit efter beitov. Vid en sadan grupp av ire rorformiga isolatorer for den ena av karnorna i en trefas 132 kV kabel, d. v. s. en kabel med 76,2 kV mellan varje ledare och jord, aro lampliga varden ph varje sektions motstand 50 MQ fOr den yttre ytan och 250 MQ for den inre ytan. I en sadan sektionerad isolator aro de hada ytorna lampligen fOrbundna med varandra vid skarvarna mellan sektionerna 15 och 16 och mellan sektionerna 16 och 17 avensom vid vardera Linden, sa att det tillforsakras, att ingen vasentlig skillnad finnes mellan spanningarna i punkter pa den inre ytan och i motsvarande punkter pa den yttre ytan. (Motsvarande punkter aro de, som ligga pit samma radiella linje Iran rarets axele) Andinuffens metalli slut bottenstyeke besthr av ett underlagsorgan 18, en nediitgaende packning 19 och en uppatgaende hylsa 20, vilka alla urn forbundna med varandra mekaniskt och elektriskt. Packningen 19 Sr for'minden med kabelns mantel 6 genom en inre fyllning av metzt11, som fatt rinna in i smolt tillstand, vid 21 och genom en overgangsskarv 22. Hylsan 20 upptager Linden av sektionen 17 av isolatorn, som Sr fast pit kiint salt med Portlands-cement, vilket erbjuder tillraeklig ledningsformaga mellan hylsan 20 och den ledande glasyren pa den yttre ytan av isolatorsektionen 17. The attached drawing shows a practical application example of the winding, whereby rite. The figure is a central longitudinal section through a duck sleeve. Another example is the insulating tube of porcelain with the conductive layers on the inner and tire surfaces provided with glazes. The dashed lines below the surfaces of the pipe are intended to indicate the presence of the conductive layers on the surfaces. IlOret Sr done 1 Ire sections 15, 10 and 17. When applied liiisaninans they are suitable for a particularly high voltage. FLU- a hire spanning can Iva sections or a single section anyandas alit after beitov. In such a group of tubular insulators for one of the cores in a three-phase 132 kV cable, i.e. a cable with 76.2 kV between each conductor and ground, the suitable values of each section resistor are 50 MQ for the outer surface and 250 MQ for the inner surface. In such a sectioned insulator, the hot surfaces are suitably connected to each other at the joints between sections 15 and 16 and between sections 16 and 17 as well as at each Linden, so that it is ensured that there is no significant difference between the stresses at points on the inner surface and at corresponding points on the outer surface. (Corresponding points are those which lie on the same radial line of the axis of Iran) The gasket 19 is formed by the sheath 6 of the cable through an inner filling of metzt11, which is allowed to flow into the molten state, at 21 and through a transition joint 22. The sleeve 20 receives Linden from section 17 of the insulator, with which Portland cement, which provides sufficient conductivity between the sleeve 20 and the conductive glaze on the outer surface of the insulator section 17.

Ovanfor Linden av manteln 6 skjuter ett kort stycke av den ledande skarmen 9 fram, -vilken ligger pa utsidan av kabelisoleringen 10. Denna skarn) Sr bildad av perforerat metalliserat 'nipper. Med dess ovre ande Sr f5rbunden en ihalig konisk metallkropp 11, som stracker sig utat med lamplig krokning till den inre ytan av isolatorn 17 och bar sorjer for den onskade fordelningen av del elektriska faltel i omradet mellan skarmen 9 och den ledande glasyren ph den inre ytan av Isola-torn 17. Above the Linden of the sheath 6 protrudes a short piece of the conductive shield 9, which lies on the outside of the cable insulation 10. This core is formed by perforated metallized nipper. Connected to its upper spirit is a hollow conical metal body 11, which extends outwards with a lamplike hook to the inner surface of the insulator 17 and carries means for the desired distribution of some electric folds in the area between the screen 9 and the conductive glaze ph the inner surface. of Isola Tower 17.

Den undre Linden av isolatorns 17 inre yta Sr fOrsedd med ett skikt av mycket hOgre ledningsformaga an glasyren, t. ex. genom elektrolytisk utfallning av metall, i omr.adet me- Ian isolatorns underkant och den koniska kroppens 11 overkant. Delta skikt Sr visat vid 28. For att frambringa forbindning mellan detta skikt och underlagsorganet 18 aro fyra ljaderkontaktbIad 24 monterade p5 lika avstand runt omkretsen ay oppningen 1 underlagsorganet och stracka sig uppat sa tat de overlappa anden av isolatorn. Pa detta satt Sr elektrisk forbindelse astadkommen mellan underlagsorganet 18 och skarmen 9 och de hada skikten av ledande glasyr pa de inre och yttre ytorna av det isolerande organet 17. The lower linden of the inner surface of the insulator 17 is provided with a layer of much higher conductivity than the glaze, e.g. by electrolytic precipitation of metal, in the area between the lower edge of the insulator and the upper edge of the conical body 11. Delta layer Sr shown at 28. To provide a connection between this layer and the substrate member 18, four ladder contact plates 24 are mounted at equal distances around the circumference of the opening 1 of the substrate member and extend upwardly so that they overlap the spirit of the insulator. On this, an electrical connection was established between the base member 18 and the screen 9 and they had layers of conductive glaze on the inner and outer surfaces of the insulating member 17.

FOr forbindning av de hada sektionerna 17 och 16 med varandra duo dents angransande andar fOrsedda med hylsor 25 och 26, vilka vardera duo fastcementerade pa sin isolatorsektion. Vid sammansattningen av sektionerna inlagges niellan (Tessa hada hylsor 25 och 26 en metallplatta 27, och de tre delarna tillsammans av bullar 28. Nara Linden av vardera av dessa sektioners inre ytor aro band av god ledningsfOrmaga anordnade, t. ex. genom elektrolytisk utfallning av metall, mid 29 och 30. Pd den lure kanten av plattan 27 aro fyra fjaderkontalithlad 31 monterade, vilha stracka sig uppilt eel) nedat och Ora kontakt med ytorna 29 och 30, sa alt det upprattas effektivt ledningssammanhang mellan de inre ytorna av dessa tva sektioner och sd all de inre och yttre ytorna forbindas elektriskt sinsemellan vid sham-yen. For connecting the had sections 17 and 16 to each other, the adjacent spirits of the duo are provided with sleeves 25 and 26, each of which is fixed to its insulator section. When assembling the sections, nine (Tessa had sleeves 25 and 26 had a metal plate 27, and the three parts together were made of buns 28. Nara Linden of each of these sections' inner surfaces were bands of good conductivity arranged, e.g. by electrolytic precipitation of metal, mid 29 and 30. On the lurking edge of the plate 27 there are four spring contact sheets 31 mounted, which will extend upwards or downwards and make contact with the surfaces 29 and 30, so that an effective conduit connection is established between the inner surfaces of these two sections. and sd all the inner and outer surfaces are electrically connected to each other at the sham-y.

Sektionerna 15 och 16 aro forbundna med varandra pa samma salt som sektionerna 16 och 17. Sections 15 and 16 are connected to each other on the same salt as sections 16 and 17.

Hatten Yid den Ovre Linden av sektionen 15 bestar av en bottenring och hylsan 32 och en huvuddel 33. Den forra Lir fastcementerad pa den iivre Linden av sektionen 15 av isolatorn och upphar huvuddelen av hatten ph sin byre yta. I huvuddelen 33 Sr andkontakten 4 monterad, vilken -vid sin undre dude har en hylsa 34, i Aiken en tapp 35 pa den iivre anden av hylsan 13 Sr styrd. Denna hylsa upptager och Sr forbunden med ledaren 12 i kabeln och Sr ledande fOrenad med andkontakten 4 genom bOjliga forbindningsorgan 14. Ett band 36 av god ledningsfarmaga am anordnat ph den inre ytan av isolator)) 15 vid den owe anden. Med detta band upprfittas forbindelse genom fjaderkontaktblad 37, som aro monterade ph huvuddelen 33, sh att ledningssammanhang ernas har. The cap Yid the upper linden of section 15 consists of a bottom ring and the sleeve 32 and a main part 33. The former is cemented to the upper linden of section 15 of the insulator and lifts the main part of the cap ph its outer surface. In the main part 33 the duct contact 4 is mounted, which - at its lower dude has a sleeve 34, in Aiken a pin 35 on the upper end of the sleeve 13 is controlled. This sleeve receives and is connected to the conductor 12 in the cable and is conductively connected to the duct contact 4 by flexible connecting means 14. A band 36 of good conductivity is arranged on the inner surface of the insulator at the upper end. With this band, connection is made through spring contact blades 37, which are mounted on the main body 33, so that the conductor connections have.

Som man torde china forekommer ett litet fritt rum mellan de inre ytorna av den rot.- formiga isolatorn och den yttre ytan av kabelisoleringen 10, vilket Sr mycket mindre an det -vanligen forekommande mellanrummet. Detta rum kan vara fyllt med isolerande massa eller olja, antingen hell och hallet eller upp till en lamplig h5jd, dar den radiella pakanningen i mellanrummet har endast ett jamforelsevis lagt varde. Alternativt kunna andra slag av fyllning tillampas, t. ex. komprimerad gas, bandomlindning eller ett — —3 As will be appreciated, there is a small free space between the inner surfaces of the root-shaped insulator and the outer surface of the cable insulation 10, which is much smaller than the usual gap. This room can be filled with insulating mass or oil, either poured into the hall or up to a suitable height, where the radial packing in the space has only a comparative value. Alternatively, other types of filling can be applied, e.g. compressed gas, belt wrapping or a - —3

Claims

Patent claim:

Duct socket for a high-voltage electrical cable, in which the longitudinal voltage distribution on the cable duct insulation is determined by the voltage drop across the surface of a tubular insulator, characterized in that the insulator has a longitudinally continuous layer extending from Oxide to the other thereof on both sides. the surface and the outer surface and having a conductor shape of such size that the longitudinal voltage distribution on the insulator is determined by the voltage drop to Mid of the lacquer current through the framed layers, without the lacquer becoming unreasonably large, the conductive layer on the outer surface the right lead shape.

Duct sleeve according to claim 1, characterized in that the outer layer has a resistance in the longitudinal direction of about 1 MP per kV of operating voltage difference between the fan and the insulator and that the inner layer here has a resistance in the longitudinal direction, which several varde.

Duct sleeve according to claim 1, characterized in that the insulator Or is built up of tubular sections (15, 16 and 17) and that stress-equalizing connections (27) are provided between the inner and outer surface layers at some or all of the joints between the sections.

Duck sleeve according to claim 1, characterized in that connecting Indian a conductive surface layer and an adjacent section or flake other part (33, 20 and 18) of the duck sleeve Or is provided by means of a localized layer (29, 30, 23 and 36) of relatively high conductivity, which Or applied over part of said conductive layer in conjunction with a contact contact means (31).

5. A duct sleeve according to claim 1, characterized in that the tubular insulator Or of porcelain, which has conductive glazes on the bitten surfaces, the outer glazed surface having a longitudinal conductor shape, which Or several times (e.g. four times ) as large as the inner glazed surface. Stockholm 1048. Kungl. lloktr. P. A. Norstedt & Simon 480089